I needed to quickly encode a protobuf from the command-line, and while I pretty much immediately came across `protoc --encode` as the obvious solution, I did not find much documentation on the input textual syntax.


Here is the relevant snippet from `protoc --help`:
```text
--encode=MESSAGE_TYPE       Read a text-format message of the given type
                              from standard input and write it in binary
                              to standard output.  The message type must
                              be defined in PROTO_FILES or their imports.
```


Here are a few examples based on some quick experimentation (as opposed to looking at whatever parsing/grammar is used by protoc itself... which would probably have taken a bit more than the few minutes for the experiments below).

Assume the following proto def (coming from [prometheus](https://github.com/prometheus/prometheus/blob/master/prompb/types.proto)):

```proto

message Query {
  required int64 start_timestamp_ms = 1;
  required int64 end_timestamp_ms = 2;
  repeated prometheus.LabelMatcher matchers = 3;
}

message LabelMatcher {
  enum Type {
    EQ  = 0;
    NEQ = 1;
    RE  = 2;
    NRE = 3;
  }
  Type type    = 1;
  string name  = 2;
  string value = 3;
}
```

Then any of the following text snippets are valid input to `protoc --encode`

#### `LabelMatcher`:

```
type: EQ
name: "foo"
value: "bar"
```

```
type: EQ, name: "foo", value: "bar"
```

```
type: EQ;name: "foo";value: "bar"
```
(Note the absence of outer curly braces!)


#### `Query`:


```
start_timestamp_ms: 0
end_timestamp_ms: 100
matchers: [{type: EQ; name: "bla"; value: 'val'}]
```

```
start_timestamp_ms: 0
end_timestamp_ms: 100
matchers: [
 {
  type: EQ
  name: "bla"
  value: 'val'
 }
]

```